


The Perks Of A Hot Boyfriend

by MeGaLoTrash



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Ectobiology, Explicit Language, Explicit Sexual Content, Having Multiple Genitals At once, M/M, Multi, PWP, Papby, Threesome - M/M/M, because MAGIC, established Papby
Language: English
Status: Completed
Published: 2017-09-02
Updated: 2017-09-02
Packaged: 2018-12-22 23:52:58
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,616
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11977731
Author URL: https://archiveofourown.org/users/MeGaLoTrash/pseuds/MeGaLoTrash
Summary: Papyrus and Grillby have been together a while, but they want to try including someone else. Luckily they have similar tastes and both can't stop staring at Grillby's double.





	The Perks Of A Hot Boyfriend

**Author's Note:**

  * For [SesuRescue (Kigachan)](https://archiveofourown.org/users/Kigachan/gifts).



> Gift fic for @sesu (sorry i fail at doing drabbles and it turned into a short fic!) You're awesome and thanks for encouraging me to try it!

Papyrus’s hand stilled before knocking on the fancy looking purple door. He and Grillby had been talking about this for months, and they had arranged tonight with meticulous care. There was just something about crossing that final threshold that made him very nervous. What if something went wrong? Would he and Grillby still be the same after doing this? Would they-

“...we don’t have to do this” Grillby reassured him with an embrace from behind, interrupting Papyrus’s thoughts from the spiral they were going down.

“We Do! The Great Papyrus Doesn't Back Down From A Challenge!” Papyrus replied. 

“You don’t have to pretend Papyrus, I'm nervous too…” Grillby held him tighter, trying to calm his shaking bones “...But he knows what we want and we can stop at any time” 

Papyrus sighed and allowed himself a moment to enjoy the embrace, Grillby had a way of being able to balance him out in a moments notice. Papyrus couldn’t help wondering if his boyfriend’s counterpart would be the same. They’d met each other a few times before tonight, but it had been pretty brief and they had been a larger group, so he didn’t really know them properly. He felt guilty when Grillby had caught him staring but, after they’d spoken things through, Grillby confessed the attraction was mutual. Papyrus found comfort in being able to talk through Grillby’s conflicted feelings about being attracted to his double, it was strange how they had such similar tastes. After a few long nights of conversation it was evident both of them were willing to explore with someone else, they just had to find out if their new friend would be interested too.

Papyrus untangled himself from Grillby had softly knocked on the door. He had barely pulled his hand back before door swung open enthusiastically and he was embraced by his boyfriends double. Swirlby, which he insisted on being called to avoid confusion, had made it pretty clear he was more than interested when they had approached him. He had initially invited them back to his place immediately, but had understood when Papyrus and Grillby wanted a little more time. If there had been any doubt of his interest though, the outfit he was wearing was a dead give away. Swirlby had swapped his usual suit for something a little more... _Lewd._ The tiny shorts and waistcoat were in his usual blue colours, but there was no more to his outfit. Well apart from the novelty bow tie, seemingly there purely to tease Grillby knowing his preference for suits and ties. Not that this outfit was at all appropriate for anything but the bedroom. Papyrus didn’t quite know where to put his hands when the fire elemental threw his arms around him. If the change in temperature behind him was anything to go by, Grillby was equally enamoured by Swirlby’s outfit. 

“Thank You for coming dearies~ Can i get you anything? Tea or something sweet?” Swirlby spoke in a sing song voice as he pulled back from Papyrus before giving his double a similar embrace.

Papyrus knew he should be answering the question, but seeing the two fire elementals together made his voice hitch. From his close position he could see their similarities and differences quite clearly. His Grillby was a little broader and seemingly calmer, but Papyrus could tell his lover was bubbling with excitement under the surface. Both of their flames were sparking erratically and despite his usual respectful behaviour, Papyrus found his eyes straying down towards the faint glowing in their pants. _Wowie_. 

“N-No We’re Ok...T-Thankyou For Agreeing To, Erm- Meet Like This” Papyrus finally replied 

“I didn’t need asking twice dearie~” Swirlby moved in a little closer to him, standing just on the edge of Papyrus’s personal space as if gauging his reaction “~A Papyrus who’s like my Sans hmm? you look sweet enough to eat”

Papyrus wasn’t quite sure what came over him. Seeing this version of his usually shy and reserved Grillby was making his mind go a little hazy. Swirlby was coy, flirty and in _that outfit._ He had closed the gap between them and brought the other monster into a kiss before his mind could catch up. _They Even Taste Similar_. Papyrus delighted in catching the other monster off guard after his teasing display, and if the crackle of flames behind him were anything to go by his boyfriend was enjoying the show.

A small part of Papyrus was a little worried that his new friend may find him too forward when he pushed his tongue into Swirlby’s parted mouth. But they all knew what they were here for. Papyrus let his hands do what they wanted, caressing the fire monsters body through the tiny shorts, making Swirlby groan into his mouth. Papyrus could have spent a lot longer trying to get some more sounds from the fire elemental, but he didn’t want to get carried away too soon. It felt a little strange to have to balance more than one partner, but when he pulled away from Swirlby he felt Grillby place a comforting hand against his side. Papyrus felt reassured by his lover's touch; this was what they both wanted and he couldn’t wait to explore more. 

“Eager hmm? I like it ~ Why don’t we move this to the bedroom?” Swirlby said, not waiting for answer before he turned and lead the way. 

Grillby seemed a little more confident and eager after watching them together, he lead Papyrus as he followed Swirlby to the bedroom. Grillby sat on the bed first, before pulling papyrus onto his lap, both of them facing forward towards their new bed mate. Papyrus felt his nerves being soothed by having Grillby’s familiar warmth around him, but his soul thrummed harder when he saw Swirlby dropping to his knees in front of him. It took a lot of control not to cry out when he felt his pants being inched down and a hot pair of hands caress the bare bone. He felt Grillby’s flames flicker around him as his double wasted no time in seeking out sensitive points around his pelvis. Grillby attached his mouth to Papyrus’s sensitive vertebrae and he let out a small groan as he felt his magic take the form of a dripping orange cock. Swirlby moved his hands closer, letting one hand graze teasingly up his length. 

“Oh my~ You are a big boy aren’t you?” Swirlby praised before peeking a tongue out of his flames. 

Papyrus was glad he was being held tight by Grillby because he wasn’t prepared to feel the hot tongue place a teasing lick across the head of his cock. He trembled a little from the sudden sensation and he felt Grillby chuckle behind him. Somehow Papyrus hadn’t assumed he would be the centre of attention, but if Swirlby’s enthusiastic licks and his boyfriends exploring touch was any indication… he might need to mentally prepare himself a little more. It was hard to focus with two mouths and two pairs of hands on him, Papyrus didn’t quite know how to keep his jerking between them under control. 

Familiar fingers were prodding at just below his formed length, willing his magic to form their too. For a second Papyrus was worried, he and Grillby had played with what his magic could do but having both his dick and his pussy formed at the same time was something they’d only done a handful of times. It felt amazing, but he had a tendency to get a little loud from the over-stimulation. But with Grillby’s soothing touch, his reassuring whispers, and the hot mouth teasing his tip, Papyrus felt his magic shifting quickly. Any objections he had disappeared when he felt Grillby slip in a finger as Swirlby’s mouth took him in deeper. 

Papyrus could feel his eyes roll back in his sockets, it felt so good. Swirlby’s mouth felt so familiar to what he was used to, but the way he used it constantly reminded him it wasn’t Grillby he was bucking up into. Swirlby’s mouth was a little narrower, and his heated tongue was darting around almost frantically which was keeping him guessing. Grillby’s fingers were working in a slow rhythm as a contrast, he knew Papyrus wouldn’t be able to handle them both going at him too hard. Grillby used his other hand to shift Papyrus slightly so his legs were open wider, spreading him open for both his lovers to enjoy. Papyrus was able to tilt his head back more in this position, and he took advantage of being able to share a heated kiss with his boyfriend. 

A small groan broke their kiss. Papyrus could see Swirbly shifting his shorts to one side and using his free hand to begin prepping himself. This made him moan around Papyrus’s cock, sending strong vibrations up the length and making him gasp. Papyrus could tell he was close already, the double sensations being too much. He wanted to tell his lovers to slow down, but he knew they’d probably see it as encouragement and double their efforts. He was going to reach his peak very soon, he just needed to try to warn them. 

“I-I’m Gonna Hah-!” Papyrus moaned out as the ability to form words lost him.

In a quick movement, he felt a Swirlby’s hand clamping down on his cock while Grillby sped up his fingers. Papyrus knew what they were trying to do, he’d managed to do it once before with Grillby where he came from one stimulus only. He was mentally prepared for what to expect, but it felt so intense under two sets of eyes. He could feel his inner walls starting to clamp down as he cried out, only to jerk a second time when Swirlby dipped his head to lap up the fluids spilling out of his entrance. Having both cum and also been denied release made him whine in need, something both his lovers seemed to enjoy hearing. 

“Mmm delicious~” Swirlby drew his head up before ridding himself of his shorts properly, a fiery member standing proud between his legs “~But we can’t let you have all the fun… right Grillby?” 

Instead of an actual answer, Papyrus felt himself being lifted up and heard Grillby’s zipper being undone. Papyrus had little patience, trying to wiggle his hips down while Grillby lined himself up. The movement of his hips smeared his wetness across the tip of his boyfriend’s cock, causing them both to groan. Grillby didn’t give him much warning before he started pressing in, his free hand reaching round to stimulate Papyrus’s still hard cock. Papyrus knew he sounded a little vulgar with how loud he was being, but he never could stay quiet when Grillby filled him. The fire elemental’s magic felt so warm inside him, he moved his legs into a wider position so he could start bouncing in his boyfriend’s lap.

Swirlby seemed to be enjoying watching them both; he had a hand stroking his length lightly while his gaze was fixed upon where the other two monsters joined. Papyrus could feel his skull flush over being watched like this, but he found he was pretty excited from the feeling. He let his gaze wander over his new lover, mapping out this other’s flame patterns and wondering if he had the same sensitive points as his Grillby. Papyrus had set up a pretty fast pace already, eager to skip the build up so he was momentarily disappointed when he felt Grillby’s hands stilling his hips. 

“...are you joining us?” Grillby asked Swirlby over his shoulder, silencing any protest Papyrus may have had. 

“~I thought you’d never ask” Swirlby replied.

Swirlby gave them both a flirty wink before turning himself round as he let himself be guided towards Papyrus’s length. Papyrus guided him with shaky hands, thankful that Grillby had slowed down to a small rocking motion. He heard Swirlby hiss and his flames crackle erratically while he inched his way inside. Papyrus could do little more than whimper, being both filled and feeling the tight hot heat around his cock. It almost felt like too much, but it was so good he didn’t want it to stop any time soon. Swirlby was panting heavily as he moved more of Papyrus into him and Grillby adjusted their position accordingly. 

“C-Can I Move P-please” Papyrus whined as his lovers all but stilled. 

He heard both of them chuckle at his impatience before Swirlby started to grind his hips, making Papyrus’s cock brush against his sensitive spots. Papyrus wanted to just slam up into him but then he felt Grillby copy the movements inside him, making him choke on a moan. The movement was tantalisingly slow and sensual but it felt incredible. Papyrus was clutching onto Swirlby’s hips hard as he moaned against him, which made him grind harder but still not move properly. It was blissful agony and Papyrus was sure they were trying to drive him crazy. 

____

Papyrus felt his control wavering a little as he started bucking his hips against them both unintentionally. Rather than chastise him his lovers moaned encouragingly. Papyrus was in heaven as he set up a hard and fast rhythm. Reaching his hand around Swirlby Papyrus wrapped his Phalanges around the flame elemental’s cock. He didn’t need to move his hand too much, Swirlby was rutting against it as they moved in tandem. Grillby’s groans were softer but Papyrus knew him well. With the way they were going none of them would be able to last much longer. It just felt so good. 

“~Mhmm fuck me hard Papy!” Swirlby moaned out on a particularly hard thrust. 

Papyrus would usually be shocked by such language but the way Swirlby was bouncing on his cock vigorously made him forget himself. He wanted to fuck him hard, he wanted to be fucked hard. He could only moan in response as he moved his hips frantically back and forth. Even though he’d been the quietest, Papyrus could feel Grillby start to twitch inside him. Hot release spurted from his boyfriends cock managing to breach the top of his magic and shoot up his ribcage. Papyrus cried out from the sensation, his second orgasm ripping through his over-stimulated body. He clutched onto Swirlby’s hip hand as he continued his thrusts until the fire elemental shouted in completion and collapsed back into them. 

The position was a little awkward but Papyrus was finding it hard to think properly. He allowed Grillby to move him off his lap as Swirlby helped him down onto the bed, pulling him into a heated embrace. Papyrus felt Grillby hold him from behind and he let himself float on a blissful cloud of warmth between his two lovers. The touches they gave were light and playful but the kisses were sloppy and deep and Papyrus wasn’t sure if he’d ever truly come down from that high with the continued attention he was receiving. 

“~Mmm how about i make us some tea and then draw you a hot bath papyrus?” Swirlby said, sitting up slightly and leaning over them both. 

“T-that Sounds Lovely, But Don’t You Both?-” Papyrus said groggily before being cut off by Grillby moving to also lean over him towards Swirlby. 

“...we’d join you but-” Grillby purred while moving to tilt Swirlby’s chin towards him and bring their mouths teasingly close “-we may be a little busy” 

Papyrus felt his bones tingle with excitement as he watched his lovers kiss. He could tell neither of the flame elementals were going to let him properly rest any time soon. He couldn’t wait to see what else they had planned. 


End file.
